Field of the Invention
The present invention relates to a method for constructing an offshore wind turbine, an offshore wind turbine, and offshore wind power generating equipment, and, particularly to a method for installing a tower and an electrical product of the wind turbine.
Background Art
Offshore wind power generation has merits, compared to onshore wind power generation, in that wind conditions are good, wind turbulence less occurs, there is no constraints of land or a road, and it is relatively easy to introduce a large wind turbine. Thus, it is possible to stably and efficiently generate power or to increase the wind turbine in size.
However, compared to the onshore wind power generation, the offshore wind power generation is performed in high costs due to construction costs of a foundation of an offshore wind turbine or the offshore wind turbine and maintenance costs.
For example, as disclosed in JP-A-2006-9596, in a case of wind power generating equipment that includes a tower having an accommodation room in a bottom portion and a substation switch device provided inside the accommodation room, there is proposed a method in which a transformer is disposed on a foundation, amount base is disposed to have a support surface thereof disposed above the transformer, a switch device is positioned on the support surface of the mount base, then, the tower is disposed to cover the foundation such that the transformer, the mount base, and the switch device are accommodated in the accommodation room.
In addition, WO 2003/025392 A1 discloses a method for constructing a wind power generating device of which an object is to significantly shorten a total construction time of wind power generating equipment. In other words, in WO 2003/025392 A1, a foundation of the wind power generating equipment is constructed, then, a power module (a transformer, a switch cabinet, or the like) is disposed on the foundation, and then the tower is caused to stand upright. In addition, the power module is formed in a method of assembly as much as possible and is mounted on a carrier, and the power module is disposed on the foundation of the tower by using a crane in a case where the wind power generating equipment is constructed.
The method for constructing the wind power generating equipment is proposed in JP-A-2006-9596 and WO 2003/025392 A1; however, there is room for improvement in an offshore wind turbine. According to study by the inventors, when an installation operation in the offshore wind turbine is modified, it is possible to shorten an offshore construction time, which is taken to install a tower and an electrical product of the offshore wind turbine.
In a case where an offshore wind farm is constructed, for example, a self-elevating type work platform referred to as a self elevating platform (SEP) barge is used; however, an operation performed by using the work platform is high in costs and construction costs are increased when the construction period of an operation performed by using the work platform is prolonged. Hence, when shortening of the construction period of an operation performed by using the work platform brings about reduction in construction costs.
An object of the invention is to provide a method for constructing an offshore wind turbine, an offshore wind turbine, and offshore wind power generating equipment, in which it is possible to shorten an offshore construction period and thus it is possible to reduce construction costs of the offshore wind turbine when the offshore wind turbine is installed on a foundation.